| 摘要 |
A dynamo-electric machine includes a rotor 1 having a plurality of permanent magnets 3 and an adjustable magnetic shunt 4, for shunting the magnetic flux of at least one of the permanent magnets 3, the shunt 4 being displaceable axially between a shunting and a non-shunting position. The rotor 1 includes a magnetically anisotropic rotor core 11 and a magnetically isotropic core element 24 and extending beyond the core end to increase the flux quantity14 shunted when the shunt 4 contacts the rotor end. A further isotropic core 26 may be provided inboard of the magnets to achieve even further flux diversion 14. An end cover 28 having recesses to accommodate the ends of the core elements 24,26 may be included to define a minimum separation t4 between the shunt and the core elements. As shown in Fig 9 the cover element may have apertures adjacent the ends of core elements 24,26. The anisotropic rotor may be achieved by means of laminations and the isotropic core parts may be an electrically non-conductive material comprising a soft magnetic composite (SMC) of insulated iron powder particles. The prior art fig 2 shows an example of appropriate shunt control.
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